Lamp-socket.



E. TAYLOR @L n.11. ELKINS. i LAMP SOCKET.

l APPLIGA'lION FILED AUG. 11, 1910. i 997,588.

Patented J ulyl 1, 1911.

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EDWARD E. TAYLOR .ANDDAVID H. ELKINS, OF .AMESBURY, MASSACHUSETTS, ASSIGN- ORS T0 WILLIAM GRAY, TRADING AS GRAY & DAVIS, OF AMESBURY, M PLSSACHUd SETTS;

LAMP-SOCKET.

Specification of'Letters Patent. Patented July 11, 1911,

Application filled August .11, 1910. Serial No. 576,683.

To all whom it may concern:

Be it known that we, EDWARD E. TAir'LoR and DAVID H. ELKINs, citizens of the United States, residing at Amesbury, in the county of Essex and State of Massachusetts, have invented certain new and useful Improvements in Lamp-Sockets, of which the following is a specification.

The object of our invention is the production of an incandescent'lamp socket of such a construction that the terminals at the base of the lamp bulb andl those of the socket shall be held in close rictional contact under all conditions of service.

vWhen incandescentlamps are used upon rapidly moving vehicles, such, `for example, as automobiles, the vibration frequently causes the displacement of the' bas'eo the lamp bulb relative to the socket, or vice versa, so that one or both of the terminals are moved from contact with one or both of the socket terminals and 'the circuit is broken and the lamp extinguished. Our inventionv is designed to prevent any such displacement and to insure an unbroken circuit` at all times for the passage of the electric current through the lamp filament. lVith the above specified end in view, our invention consists in certain novelties of construction and combinations of parts as hereinafter-'set 'forth and claimed.

The accompanying drawing illustrates an example of the physical embodiment'of the invention constructed accprding to the best mode of procedure we have so far devised for the purpose. y

Figure l is` an enlarged side view of the socket and a lamp base inserted within the socket. Fig. 2 is a longitudinal sectional view of the socket shown in Fig. 1. Fig. 3 is a sectional view of the socketwith the insulating block in the relative position it assumes when 'the lamp basek is detached from the socket. Fig. llisa side view of the lamp base. Fig. 5 is an end view of the base. Fig. G is a side view of the insulating'` 'socket piece. Fig. 10is a side and end view of one of .the socket terminals.

Referring to the several figures, the numeral l designates the base of an incandescent electric lamp; 2, 2, the terminals in vconnection vwith the filament; 3, locking llugs or studs disposed `at opposite sides of the base; t, the socket piece proper consisting of a metallic cylinder, in this instance of an enlarged diameter at one end to provide a suitable recess for the head of an insulating block; 5, 5, oppositely disposed slots in the socket; 6, 6, offset seats at the closed ends of the slots to receive the studs on the base, constituting a bayonet joint; 7, the flange uniting the smaller and the larger parts ofthe socket piece; 8, 8, inwardly projecting ribs upon the inner surface of the larger end of the socket piece; 9, threads upon the exterior surface; 10, a` cylindrical cap; 11, threads on the inner surface adjacent the open end thereof; 12, an opening at one end of the cylinder; 13, an inwardly extended -ange bounding the opening; let, the insulating block of any suitable insulating material; 15, the head of. the block; 16, slots to loosely receive the ribs 8, 8 on the socket piece and prevent the rotation ot' the block upon its axis; 17, 17, two metallic terminals passed through the block longi tudinally; 18, the heads of the terminals; 19, 19, current conducting wires; and'20 is a conical coiled spring surrounding the insulating block and bearing at one end against the iia'nge lof the cap and at the other end against the surface 21 of the head of the insulating block;

It will be observed that there is clearance space 22 between the edge of the iiange 13 of thecapand the insulating block and also considerable clearance space between the inner surface of the larger part of thesocket piece andthe head .of the insulating block. These spaces are essential to allow the longitudinal axis of the block to take positions out of direct line with the longitudinal axis of the socket piece. As shown in liig. 3, the spring forces the head of the insulating block against the flange 7 of the socket piece when the lamp base is removed. lllhen the base is partly inserted within the socket the terminals 2, 2 engage the heads 18, 18 of' the4 other terminals, and ar further introduction of the base into the socket forces the insulating block longitudinally away from the flange 7 compressing the spring, so that when the base is finally seated land locked the spring forces the heads of the insulating block terminals against the base terminals and holds them in contact under all condi- 55y f V-the head at one end and the flange about tions, inasmuch as the insulating block is loose withinthe socket and cap and its axis is always held in line with the axis of the lamp base under spring pressure.

In the embodiment of our invention obviously many changes may be introduced, for instance; the loose insulating block may be used in connection with a base which is heldf within the socket by screw threads or otherwise in lieu of the bayonet joint, .and theinsulating block maybe of a different shape from that shown, all of which changesv may be made without constituting substantial departures.

Vhat we claim is:`

l. The combination in a lamp socket, of a cylindrical socket piece proper,vone end being provided withmeans for holding a lamp base and the other end threaded; a cylindrical cap with one end threaded and the other end having an opening bounded by an inwardly projecting flange; insulating material with a head and shank' looselyl disposed within the socket piece and cap and the end of the shank passed through the opening in the cap, the diameter of" the shank being sufliciently less than the diameter'of the opening, in the cap to secure a normally open space between the flange andthe shank whereby the shank is held inplace and the head and shank allowed to rock; two terminals located in the insulating material and extended longitudinally thro'ugh the head and shank; a spring vabout the shank of theinsulating material bearing against the end of the cap at the other end;'means for preventing the rotation of the insulating material about its axis; and means for limiting the longitudinal movement of the insulating material relative to the socket piecel and cap.

2. The combination in a lamp socket, .of a cylindrical socket piece proper, one end being provided with means for holding a lamp base and the other end threaded; a cylindrical cap with one end threaded and the other end having an opening bounded by an the socket piece and cap; the end of the said insulating material extending through the opening in the end of the cap, there being when the parts are assembled an open space between the flange bounding the opening through the end of the cap and the outer surface of the shank so the head and .shank can rock, and the current conduct-ing wires being secured to the two terminals projecting beyond the said cap.

3i. The combination in a lamp socket, of a cylindrical socket .piece proper having a flange 7 dividing its opposite ends into parts of smaller and larger diameters, the end' of the smaller diameter being provided with means for holding a lamp base; a cylindrical cap, having an inwardly extending flange 13 bounding an opening, detachablysecured to the socket piece; an insulating block having a shank and a head 15 loosely disposed. within the larger end ofthe socket piece and the cap with its shank passed through the opening bounded by flange 13, whiehopening is of greater diameter than the diameter of the shank to provide an open space between the flange and shank so the latter can rock to a limited degree and still be con-t fined against excessive displacement through the medium of the flange:

In testimony whereofweaffix our signatures in presence of two witnesses.

EDWVARD E. TAYLOR. DAVID H. ELKINS. Vitnesses:

ALFRED P. 'HARTSHORM THoMAs F. ONEIL. 

